1. Field of Invention
The invention relates to a motor and a coil structure thereof and, in particular, to a motor and a coil structure of the FaulHaber winding type.
2. Related Art
Motors are commonly used devices for converting electricity into mechanical energy, thus applied to various kinds of machines such as fans, CD-ROM drivers, hard disk drivers, optical devices, or car devices. There are various kinds of the motor, and they principally function by the electromagnetic effect.
In general, the motor has a magnet as a rotor, and a coil structure as a stator, and can be divided into an external-rotor type and an internal-rotor type in structure. For the external-rotor type, the permanent magnet of the motor is disposed at the outside of the coil stator.
The hollow coil of the present DC motor (regardless of the brushless type or the brushed type) is formed by winding the enameled wire to the hollow circular shape without any permeance iron core been covered by the enameled wire. There are many winding types for a hollow coil, winding types such as hexagon winding, bell-type winding, or diamond winding. FIG. 1A shows a coil 1 with the FaulHaber winding type, in which the enameled wire is bent to conduct the winding, and from appearance the main characteristic of the coil 1 is winding towards the diagonal direction.
As shown in FIG. 1B, the coil 1 is unfolded, including a triangle and an inverted triangle to form a triangle pair (the areas a and b constitute a triangle, and the area c is an inverted triangle, so that a triangle pair is formed). For the coil 1, the triangle portion provides the positive exciting, and the inverted triangle portion provides the negative exciting, thereby rotating the rotor by the switch driving of the circuit. The DC motor presently produced by the industry has a triangle pair (as shown in FIG. 1B) or two triangle pairs (as shown in FIG. 1C, the areas d and e constitute a triangle, and the areas f, g, and h are respectively a triangle, all of which constitute two triangle pairs). Besides, as shown in FIG. 1D, when the hollow coil of the motor has a triangle pair, it can only cooperate with one magnet pair (e.g. with a pair of N-pole and S-pole). When the hollow coil of the motor has two triangle pairs, it can cooperate with two magnet pairs (e.g. four poles, not shown in FIG. 1D). In other words, the number of the magnets is two times the number of the triangle pair.
If the motor will provide more torsion or produce more power with the same motor volume, it needs to cooperate with more magnet pairs, and thus the FaulHaber winding type needs to produce more triangle pairs. To form more triangle pairs, the enameled wire needs to be bent more times, but this will result in the smaller angle θ. The smaller angle θ indicates the enameled wire is bent more greatly, and this will cause the crack to the bent portion of the coil. Consequently, some problems such as the current leakage, less insulation, or lack of pressure resistance will occur to the coil.
Therefore, it is an important subject to provide a motor and a coil structure thereof that can have more magnetic materials with the same bending angle, so that the motor can output larger torsion and power to enhance the motor efficiency.